Reversible hydraulic torque applier



Filed Oct. 50, 1961 E. E. SHIPLEY 2 Sheets-Sheet 1- p CONTROL on. 49 F|G.2

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EUGENE E. SHIPLEY.

HIS ATTORNEY.

Aug. 20, 1963 E. SHIPLEY REVERSIBLE HYDRAULIC TORQUE APPLIER 2 Sheets-Sheet 2 Filed Oct. 30, 1961 REVERSE TORQUE FORWARD TORQUE Qw'llmm V ///1 Wm INVENTOR'. EUGENE E. SHIPLEY. BY 40, 6". m

HIS ATTORNEY.

United States Patent M 3,168,991 REVERHBLE HYDRAULIC TORQUE APPLIER Eugene Shipley, Middleton, Mass assignor to General Electric Company, a corporation of New York Filed Get. 3%, 1961, Ser. No. 148,415 2 Qlainis. (Cl. 73-162} This invention relates to a hydraulic torque applier for test-loading the gears in a locked gear train, and more particularly applies to a reversible torque applier which is unaffected by variations in speed or temperature.

Gears or other torque transmitting members are often tested by connecting them in a locked train and rotating them with an external power source. Various arrangements have been suggested to apply additional torque to the gears in the locked train while it is rotated, in order to simulate increased or decreased torque under actual conditions while the gear train is transmitting a load. It is also desirable, in some cases, to determine the elfects of reverse torque on the gear members while the system is in motion, and one such arrangement is disclosed in U.S. Patent 2,371,607, Collins issued March 20, 1945 and assigned to the assignee of the present application. In that device, an unavoidable axial thrust was placed on the shafts by the opposed helical gears which produced the application of torque. This undesirable effect of imposing a thrust as torque was applied was substantially eliminated by the torque-applying device disclosed in my U.S. Patent 2,935,869 issued May l0, 1960 and assigned to the same assignee. However, in that device, there is no means for reversing the torque without stopping the test and reconnecting the elements. Also, the torque applier was sensitive to variations in speed and also to variations in oil temperature which change the density of the 'oil. This invention is an improvement over the device of the aforementioned U.S. Patent 2,935,869.

Accordingly, one object of the present invention is to provide an improved arrangement for applying torque to a locked gear train while the gear train is rotated by an external power source, which torque may be applied in either direction without imposing substantial axial thrust on the members.

Another object of the invention is to provide an improved means for reversing the torque in a hydraulic torque applier while the torque applier is rotating.

Another object of the invention is to provide an im proved torque tapplier, wherein variations in applied torque due to speed changes or variations in oil temperature are substantially eliminated.

Still another object of the invention is to provide an improved arrangement for reversing the roles of torque applying chambers and drain chambers in a hydraulic torque applier so as to reverse the torque.

The subject matter which is regards as the invention is particularly pointed out and distinctly claimed in the concluding portion of this specification' The invention, however, both as to organization and method of practice, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a diagrammatic illustration of the torque applying device connected in apparatus for testing a locked gear train;

FIG. 2 is a cross-sectional view through the axis of the torque-applying device;

FIG. 3 is a perspective view, partially in section, of the torque-applying device;

'FIG. 4 is a diagrammatic illustration of the manner in which forward torque is applied; and p 3,100,991 Patented Aug. 20, 1963 FIG. 5 is a similar diagrammatic illustration of the manner in which reverse torque is applied.

Briefly stated, the invention is practiced by employing a reversing valve in the bore hole of the torque applier rotor which selectively connects a source of hydraulic fluid to either of two alternating sets of circumferentially spaced chambers while connecting the other intervening set to a drain also located in the bore hole. The radial conduits connecting the bore hole to the respective sets of chambers are of equal length to balance the effects of centrifugal force. Means are provided to change the position of the reversing valve while the torque applier is rotating.

Referring to FIG. '1, the device comprises driven and drive shafts 1, 2 respectively which are interconnected through coupling 3 and the torque applier 4. Secured to shaft '1 is gear 5 which engages idler gear 6. Idler gear 6, in .turn, engages gear 7 on shaft 12, which is rigidly connected to shaft 11 by coupling 13. Mounted on shaft 11 is gear Ill which rotates gear 8 on shaft 2 through idler 9. Thus an interconnected gear set or locked train is formed, so that when any of the members is rotated with respect to an adjacent member, a torque is applied and each of the gears in the set is loaded. The interconnected gear train is driven by motor 14 which is connected to shaft 2 through a coupling 15.

Referring to FIGS. 2 and 3, the torque applied 4 comprises a rotor 16 with a main body portion 16a and spindle portions 16b, and also defining an axial bore hole 17. The left end of rotor spindle portion 16b terminates in a splined connection 18 connected to a plate 19 bolted to shaft 1. Rotor 16 also includes ciroumferentially spaced radial paddles 19.

Torque applier 4 also includes a housing shown generally at 2% and comprising opposite radial end members 20a, Zllb to which is pinned a, circumferential outer wall 200. Housing 29 is rigidly connected to flange Zn on shaft 2 by means of bolts 21. Disposed in grooves 22 (FIG. 3) of housing end walls Zita, 20b are a number of circumferentially spaced radial paddles 23.

Housing 20 is mounted so as to be rotatable relative to rotor 15 by means of needle bearings 24 disposed between rotor spindles leb and the bores of the housing end Walls 20a, 29b. Also fluid pressure chambers 25 are defined between the housing 2% and the rotor 16. These are divided up into alternating series of chambers 25a, 25b, 25a, 251;, etc. (see 'FIG. 3) by the alternating sets of paddles 1 9, 23 disposed on the rotor 16 and housing 2% respectively. Therefore, applying fluid pressure to all chambers 25a while draining all chambers 25b will cause a torque to be exerted between the housing 20 and the rotor 16 without imposing axial thrust on the shaft members 1, 2.

In order to actuate the torque-applier, hydnaulic fluid is introduced into bore hole '17 through conduit 26 (FIG. 2) and is furnished under pressure from a supply tank 27 by a pump 28. The flow is regulated by a valve 29 and a pressure regulator 30 in response to a suitable signal 31. The pressure is indicated by means of a gauge 32 and is proportional tothe torque applied on the locked gear train.

The foregoing description of the torque-applying device is substantially the same as the torque-applying device described in the aforementioned U.S. Patent 2,935,869.

In accordance with the present invention, two sets of radial conduits supply the alternate series of fluid pressure chambers 25a, 25b. The first set, one of which is indicated as '33 in FIG. 2, connects each of the chambers 25a with bore hole 17. Conduit 33 branches to provide two axially spaced ports 33a, 3315 opening into the bore hole 17. Conduit 33 also terminates at its a radially outer end as a portfific opening into chamber 25a.

Although only a single conduit with parallel lower branches is shown, conduit 33 could consist equally well of two parallel, axially-spaced radial holes leading from chamber 25a to ports 33a, 331), respectively. Port 33c is located very near the edge of rotor paddle 19 (see FIG. 3) so as not to be covered by housing paddle 23: when it moves.

The second set of conduits, one of which is indicated as 34 in FIG. 2, has a port 34a opening into the bore hole approximately axially midway between port 33a, 33b. Conduits 34 also terminate at their outer ends in ports 34b opening into each of the series of chambers 25b. (See 'FIG. 3). Ports 34b are located near rotor paddles 19 for the same reason as ports 33c.

Disposed in bore hole 17 is a reversing valve 35 which directs the flow of hydraulic fluid to and from conduits 33, 34. Valve 35 comprises a cylindrical section 36 defining ports 36a, 361). A radial wall 37 blocking access along thebore hole is disposed between ports 36a and 36b. Reversing valve ports 36a, 36b are axially spaced so as to be aligned either with conduit ports 33a, 34:: as shown in FIGS. 2, 4, or alternately with ports 34a, 3315, when the reversing valve is in its other position, as shown in FIG. 5. In order to move reversing valve 35 to either of its two positions, while the members are rotating, one suitable means comprises a hydraulic actuator best seen in FIG. 2 of the drawing. There a reduced diameter cylindrical portion 38 forming an extension of pilotvalve cylinder 36 defines a small piston 39 near the mid portion thereof which, in turn, defines close clearances with the walls of bore hole 17. Stops 40, 41 serve to limit the movemerit of reversing valve to either of two positions and combination sealing and abutment rings '42, 43 serve to seal off pressure chambers on either side of piston 39. Communicating with these pressure chambers are radial ports 44, 45 defined in the rotor spindle 16b. A collar 46 furnished with suitable rotating seals and fitted with pipes 47, 48 serves to supply hydraulic fluid to and from ports 44, 45 while the spindle is rotating.

A source of control oil from a tank 49 and supplied through pump 50 is selectively connected to either pipe 47 or pipe 48 while the other pipe is drained by means of a pilot valve 51, as will be apparent from. the drawing. Shifting the pilot valve stem '52 in one direction or the other will pressurize one or the other chambers on the 7 sides of piston 39 and serve to shift reversing valve 35 to and fro in the bore hole as desired. As will occur to those skilled in the art, the fluid supply for pilot valve 51 can also be taken from conduit 26 which actuates the torque applier.

The manner in which the torque-applier reverses the torque by merely shifting a valve in the bore hole may be seen more clearly by reference to the diagrammatic illustrations in FIGS. 4 and 5. There a developed plan view of the housing 20* is shown, together with its radial paddles 23- considered as a portion thereof, While the rotorpaddles are designated by numeral 19. The radial conduits 33 have been displaced from the centerline so as not to confuse the drawing.

' In FIG. 4 the reversing valve 35 is shown in the lefthand or forward torque position with the hydraulic fluid from borehole 17 flowing through valve ports 36b, conduits '34 and out of ports 34b into chambers 25b. Any oil leaking into chambers 25a is free to flow out through ports 33c and conduits 33 and thence through valve ports 36a, and out the opposite end of the bore hole. The wall 37 prevents flow through the bore hole directly from the fluid pressure source to the drain. Sincethe I pressure in each of the chambers 25b is greater than the pressurejin corresponding chambers 25a, a force will be exerted on the circumferentially spaced walls as indicated by arrows 53, thereby causing a torque between the rotor and the housing.

Referring to FIG. 5, the reverse torque flow diagram,

it will be seen that reversing valve 35 has been shifted to the righthand position and theradial flow of oil is reversed with the oil entering through valve ports 36b in and flowing through conduits 3 3 and out of ports 330 into each of the chambers 25a. On the other side of the rotor paddles 19, leakage oil is free to flow out through ports 34b, conduit 34 and through valve ports 36a to the drain. Thus the radial conduits serve the dual function of supply and discharge conduits and reverse their roles as the reversing valve 35 is shifted in the bore hole.

By reference to FIG. 2 of the drawing, it will be seen that the radial distance from the bore hole 17 to outlets 330 of the conduits 33 is the same as the radial distance from the bore hole to the outlets 3 21) of conduit 34. Therefore, any effects of centrifugal force due to variation in speed or variation in oil density due to temperature change are eliminated from the differential pressure existing between chambers 25a and chambers 25b. Therefore, the pressure difference between these chambers will be more fully and accurately representative of the torque exerted by the hydraulic fluid than it would be if conduits 33, 34 were of different radial lengths or if the spent oil were not returned to the bore hole. The torque indicated by the device 32 is thus proportion-a1 only to the static head'of oil and is constant for any speed or temperature condition.

The hydraulic actuator for reversing valve 35, controlled by pilot valve 51, allows the reversing va.ve to be actuated while the torque-applier is rotating. Although the reversing valve could, be manually actuated or other devices could be shown to shift the reversing valve axially while the torque-applier was rotating, the hydraulic actuator shown is particularly useful for smoothly effecting reversal of torque.

The improved torque-applier shown is useful to apply torque to a locked gear train while the gears are rotating, operating at a variety of speeds over a wide temperature range without recalibration, and for either direction of torque application required. Almost any condition of loading can be achieved through the manipulation of the pilot valve 51 and the pressure regulator 30', without stopping the equipment.

While there has been described herein what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a rotatable hydraulic torque-applier for applying torque to the gear members of a locked gear train while the gear members are rotating, the combination of:

' a rotor defining a bore hole along the axis thereof and having a plurality of circumferentially spaced radially extending paddle members,

a rotatable housing disposed around said rotor and having a plurality of circumferentially spaced paddle members defining together with said rotor paddle members first and second series of alternating circumferentially spaced chambers between said respective rotor and housing paddle members,

a source of fluid under pressure connected to said rotor bore hole,

first conduit means connected between each of said first series of chambers and the bore hole and terminating on the radially inner end at ports defined at two axially spaced locations in the bore hole,

second conduit means of the same radial length as said first conduit means and connected between each of said second series of chambers, and the bore hole and terminating on the radially inner end at ports defined by the bore hole between said first axially spaced conduit ports,

axially slidable reversing valve means disposed in the bore hole and defining two axially spaced sets of ports cooperating with said first and second conduit ports, said reversing valve being movable to first and second positions for selectively connecting either said first or second series of chambers to said fluid pressure source while draining the other series of chambers through the bore hole,

and means for axially shifting the position of said reversin g valve means while the members rotate, whereby torque may be applied between rotor and housing in either direction.

2. In a rotatable hydraulic torque applier for applying torque to the gear members of a locked gear train while the gear members are rotating, the combination of:

a rotor defining a bore hole along the axis thereof and having a plurality of circu-mferentially spaced radially extending paddle members,

a rotatable housing disposed around said rotor and having a plurality of circumferentially spaced paddle members defining together with said rotor paddle members first and second series of alternating circumferentially spaced chambers between said respective rotor and housing paddle members,

a source of fluid under pressure connected to said rotor bore hole,

first radial conduit means connected from each of said first series of chambers to the bore hole and defining inner terminating ports in the bore hole at two axially spaced locations,

second radial conduit means of the same radial length as said first conduit means and connected between each of said second series of chambers and the bore hole and defining inner terminating ports axially spaced midway between said first conduit ports,

reversing valve means disposed in the bore hole, and

including an axially slidable cylindrical portion having a radial wall blocking flow axially through the bore hole, said cylindrical portion defining ports on either side of said radial wall and arranged to register with the first and second conduit ports in either of two axial positions,

hydraulic actuator means comprising piston means connected to said reversing valve cylindrical member and defining third and fourth pressure chambers with the rotor, and also including means to supply fluid to either side of said piston means while the rotor is turning, whereby torque may be applied between rotor and housing in either direction while the memhere are turning.

References Cited in the file of this patent UNITED STATES PATENTS 2,147,761 Whitoomb Feb. 21, 1939 2,371,607 Collins Mar. 20, 1945 2,935,369 Shipley May 10, 1960 FOREIGN PATENTS I 697,586 Germany Oct. 17, 1940 

1. IN A ROTATABLE HYDRAULIC TORQUE-APPLIER FOR APPLYING TORQUE TO THE GEAR MEMBERS OF A LOCKED GEAR TRAIN WHILE THE GEAR MEMBERS ARE ROTATING, THE COMBINATION OF: A ROTOR DEFINING A BORE HOLE ALONG THE AXIS THEREOF AND HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED RADIALLY EXTENDING PADDLE MEMBERS, A ROTATABLE HOUSING DISPOSED AROUND SAID ROTOR AND HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED PADDLE MEMBERS DEFINING TOGETHER WITH SAID ROTOR PADDLE MEMBERS FIRST AND SECOND SERIES OF ALTERNATING CIRCUMFERENTIALLY SPACED CHAMBERS BETWEEN SAID RESPECTIVE ROTOR AND HOUSING PADDLE MEMBERS, A SOURCE OF FLUID UNDER PRESSURE CONNECTED TO SAID ROTOR BORE HOLE, FIRST CONDUIT MEANS CONNECTED BETWEEN EACH OF SAID FIRST SERIES OF CHAMBERS AND THE BORE HOLE AND TERMINATING ON THE RADIALLY INNER END AT PORTS DEFINED AT TWO AXIALLY SPACED LOCATIONS IN THE BORE HOLE, SECOND CONDUIT MEANS OF THE SAME RADIAL LENGTH AS SAID FIRST CONDUIT MEANS AND CONNECTED BETWEEN EACH OF SAID SECOND SERIES OF CHAMBERS, AND THE BORE HOLE AND TERMINATING ON THE RADIALLY INNER END AT PORTS DEFINED BY THE BORE HOLE BETWEEN SAID FIRST AXIALLY SPACED CONDUIT PORTS, AXIALLY SLIDABLE REVERSING VALVE MEANS DISPOSED IN THE BORE HOLE AND DEFINING TWO AXIALLY SPACED SETS OF PORTS COOPERATING WITH SAID FIRST AND SECOND CONDUIT PORTS, SAID REVERSING VALVE BEING MOVABLE TO FIRST AND SECOND POSITIONS FOR SELECTIVELY CONNECTING EITHER SAID FIRST OR SECOND SERIES OF CHAMBERS TO SAID FLUID PRESSURE SOURCE WHILE DRAINING THE OTHER SERIES OF CHAMBERS THROUGH THE BORE HOLE, AND MEANS FOR AXIALLY SHIFTING THE POSITION OF SAID REVERSING VALVE MEANS WHILE THE MEMBERS ROTATE, WHEREBY TORQUE MAY BE APPLIED BETWEEN ROTOR AND HOUSING IN EITHER DIRECTION. 